diff --git a/dumux/material/binarycoefficients/h2o_air.hh b/dumux/material/binarycoefficients/h2o_air.hh new file mode 100644 index 0000000000000000000000000000000000000000..f5be176523e9c9a7fbf87dad0b2d30fadc004600 --- /dev/null +++ b/dumux/material/binarycoefficients/h2o_air.hh @@ -0,0 +1,117 @@ +/***************************************************************************** + * Copyright (C) 2011 by Holger Class * + * Copyright (C) 2009 by Andreas Lauser * + * Institute of Hydraulic Engineering * + * University of Stuttgart, Germany * + * email: <givenname>.<name>@iws.uni-stuttgart.de * + * * + * This program is free software: you can redistribute it and/or modify * + * it under the terms of the GNU General Public License as published by * + * the Free Software Foundation, either version 2 of the License, or * + * (at your option) any later version. * + * * + * This program is distributed in the hope that it will be useful, * + * but WITHOUT ANY WARRANTY; without even the implied warranty of * + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * + * GNU General Public License for more details. * + * * + * You should have received a copy of the GNU General Public License * + * along with this program. If not, see <http://www.gnu.org/licenses/>. * + *****************************************************************************/ +/*! + * \file + * + * \brief Binary coefficients for water and nitrogen. + */ +#ifndef DUMUX_BINARY_COEFF_H2O_AIR_HH +#define DUMUX_BINARY_COEFF_H2O_AIR_HH + + +namespace Dumux +{ +namespace BinaryCoeff +{ + +/*! + * \ingroup Binarycoefficients + * \brief Binary coefficients for water and nitrogen. + */ +class H2O_Air +{ +public: + /*! + * \brief Henry coefficent \f$\mathrm{[N/m^2]}\f$ for air in liquid water. + * + * + * Henry coefficent See: + * Stefan Finsterle, 1993 + * Inverse Modellierung zur Bestimmung hydrogeologischer Parameter eines Zweiphasensystems + * page 29 Formula (2.9) (nach Tchobanoglous & Schroeder, 1985) + * + */ + template <class Scalar> + static Scalar henry(Scalar temperature) + { + Scalar r = (0.8942+1.47*exp(-0.04394*(temperature-273.15)))*1.E-10; + + return 1./r; + }; + + /*! + * \brief Binary diffusion coefficent \f$\mathrm{[m^2/s]}\f$ for molecular water and air + * + * \param temperature the temperature \f$\mathrm{[K]}\f$ + * \param pressure the phase pressure \f$\mathrm{[Pa]}\f$ + * Vargaftik : Tables on the thermophysical properties of liquids and gases. John Wiley & * Sons, New York, 1975. + * + * Walker, Sabey, Hampton: Studies of heat transfer and water migration in soils. + * Dep. of Agricultural and Chemical Engineering, Colorado State University, + * Fort Collins, 1981. + */ + template <class Scalar> + static Scalar gasDiffCoeff(Scalar temperature, Scalar pressure) + { + const Scalar Theta=1.8; + const Scalar Daw=2.13e-5; /* reference value */ + const Scalar pg0=1.e5; /* reference pressure */ + const Scalar T0=273.15; /* reference temperature */ + Scalar Dgaw; + + Dgaw=Daw*(pg0/pressure)*pow((temperature/T0),Theta); + + return Dgaw; + }; + + /*! + * Lacking better data on water-air diffusion in liquids, we use at the + * moment the diffusion coefficient of the air's main component nitrogen!! + * \brief Diffusion coefficent \f$\mathrm{[m^2/s]}\f$ for molecular nitrogen in liquid water. + * + * The empirical equations for estimating the diffusion coefficient in + * infinite solution which are presented in Reid, 1987 all show a + * linear dependency on temperature. We thus simply scale the + * experimentally obtained diffusion coefficient of Ferrell and + * Himmelblau by the temperature. + * + * See: + * + * R. Reid et al.: "The properties of Gases and Liquids", 4th edition, + * pp. 599, McGraw-Hill, 1987 + * + * R. Ferrell, D. Himmelblau: "Diffusion Coeffients of Nitrogen and + * Oxygen in Water", Journal of Chemical Engineering and Data, + * Vol. 12, No. 1, pp. 111-115, 1967 + */ + template <class Scalar> + static Scalar liquidDiffCoeff(Scalar temperature, Scalar pressure) + { + const Scalar Texp = 273.15 + 25; // [K] + const Scalar Dexp = 2.01e-9; // [m^2/s] + return Dexp * temperature/Texp; + }; +}; + +} +} // end namepace + +#endif